Location, Location, Location

India is the snakebite capital of the world. 

About half of all snakebite deaths occur in India, killing as many as 138,000 people annually. 

And the main perpetrator, the Russell’s viper, or Daboia russelii, which is common on the Indian subcontinent, maims or kills more people than any other species of snake. 

“As a result, it is important to precisely unravel the composition, activity, and potency of Russell’s viper venoms and understand the role of biotic and abiotic factors in shaping them,” said Kartik Sunagar, the author of a new study on the snake and how its venom impacts humans, in a statement. 

According to the study, the snake’s venom changes across regions, meaning that a person bitten in one location will show different symptoms than another bitten by the same snake somewhere else, according to Cosmos Magazine. 

That’s because a combination of climatic factors – temperature and precipitation, researchers said.  

Previous research has shown that biotic factors – like dietary changes during development – may affect the composition and toxicity of Russell’s viper venom. However, the consequences of abiotic – environmental factors have not been studied until now. 

To arrive at the conclusions, the researchers analyzed venom samples from 115 snakes collected at 34 locations across India. They then used historical climate data to examine how venom composition relates to local climates, which can vary significantly even over short distances. 

The study showed that the Russell’s viper venom from dryer regions contained more protein-degrading enzymes, a major component of the venom that causes the most serious symptoms for humans who have been bitten. 

Other venom components showed no correlation with climate. 

With this data, the team created a map predicting venom types across the range of Russell’s vipers in India to predict the symptoms of the bite depending on the region, findings that could help doctors decide on the most appropriate treatment. 

Correction: In our top story on Canada’s election Monday, we quoted a voter who spoke to the Canadian Broadcasting Commission. He, in fact, spoke to the Canadian Broadcasting Corporation. We apologize for the error.